I saw Phil Morris (Jackie Chiles) on The Love Boat, a terrible show which makes the weakest Seinfeld look like Shakespeare. He is quite normal in it, nothing like his Jackie Chiles character.
Richard Herd (Mr. Kruger, a boss of George's) has quite a large role in The Postman. Since the film was universally panned and ignored, he was wasted in it. He's quite a good actor. Also quite different than he was on Seinfeld. He was also in the Meryl Streep film, Before and After.
The only actor who really is exactly the same as she was on Seinfeld is: "Sally" (Kathy Griffin, on Suddenly Susan). A while ago many here commented on how repellant she was in her two episodes with Jerry. I guess they would hate Suddenly Susan too - I do, but not because of her. It's a boring show. Did you read the TV Guide article explaining how the plot of her second appearance on Seinfeld was based on her real life act where she was critical of Jerry? It was his idea to put it in the script.